The day 8-year-old Sandra Cantu disappeared from a Tracy, Calif., mobile-home park, Melissa Huckaby sent a text message to the child's mother.

"Tell the police that I had something stolen today around 4 p.m.," Huckaby texted to Maria Chavez on March 27, 2009. "I don't know if that makes a difference or not."

That stolen item turned out to be an Eddie Bauer suitcase that contained Cantu’s body, the victim of a brutal sexual assault and murder.

The case horrified the Central California community, but even after Huckaby pleaded guilty and was sentenced to life in prison, residents were at loss as to why the Sunday school teacher committed such a heinous crime against her own daughter's playmate.

Now, with thousands of pages of previously sealed documents released and the lifting of a gag order, authorities are offering a theory: The bizarre text message and Huckaby's subsequent strange behavior suggested she killed the child in an attempt to attract attention to herself.

A Theory for Motive

Such behavior has a name: Munchausen by Proxy Syndrome, a form of child abuse, in which a person harms somebody else, often children, for attention. The prosecutor in the case noted that Huckaby's daughter may also have fallen victim: the child had a history of being sick and in need of hospital care way too often.

"There were 20 or so times that Melissa cut herself, set fires, or verbally or psychologically attacked someone else, such as a roommate," says Deputy District Attorney Thomas Tesla. "And there was something like that going on here (after the murder), where she wanted to be the center of attention."

The text message was just one clue. Also, the day after Sandra disappeared, Huckaby was hysterical and hyperventilating as she went to police to say she had found a note on lined notebook paper.

Newly Revealed Evidence

The misspelled message stated Sandra's body was locked in a stolen suitcase thrown in water at Bacchetti and Whitehall roads. "I wonder if she wanted to be the one who solved the case by finding the note," Tesla suggests.

Investigators thought it unusual that a woman who reported losing a suitcase "should be the one woman out of everyone in this complex who should happen to find a note that reports that the stolen suitcase was used to hide the child's body," FBI Special Agent Michael Conrad would testify in the grand jury, according to transcripts.

During an April 6 search of Huckaby's home after the suitcase was recovered, FBI agents found a notebook with "Cute but psycho. Things will even out" printed on the cover. On the pages they found indentations matching the letters from the note.

"It didn’t take an FBI expert to figure this out," Tesla says. "She has a distinctive way of writing certain letters. You can compare it to her known handwriting… and tell as a layperson that they’re written by the same person."

When confronted with the mounting evidence, court documents show, Huckaby offered a confession of sorts, saying that Cantu hid in the suitcase in Huckaby’s trailer as part of a game, but stayed inside too long and suffocated. Huckaby also offered a soft version of the events at her sentencing, saying Sandra "didn't suffer. I didn't sexually molest her."

But, Tesla contends, forensic evidence offers a grimmer version of the crime: Huckaby took Cantu to her grandfather’s nearby church, sexually molested her with a rolling pin, strangled her and stuffed her into the suitcase in a snug fetal position that Cantu couldn’t have squeezed into on her own. Huckaby then tossed the suitcase into an agricultural ditch that stunk so badly of manure that searchers couldn’t retrieve the suitcase until it eventually floated to the surface.

In the first few days of the investigation, detectives assumed the killer was a man. They trailed local sex offenders and investigated their alibis. Says Tesla: "We thought there was no way a woman would do these things."